Showcase assembly unit for showcase structure

ABSTRACT

A showcase assembly unit for the showcase structure is disclosed, which includes a roller support frame and a plurality of parallel sets of rollers mounted on the roller support frame, wherein the rollers in each set of rollers are mounted rotatably and arranged one after another from the rear end toward the front end of the roller support frame, and a plurality of individual articles, such as canned foods or drinks, may be placed across two or more parallel sets of rollers and are capable of moving one by one from the rear end toward the front end of the roller support frame.  
     In the showcase assembly unit for the showcase structure according to the present invention, each roller has a specific width that is smaller than the size of the bottom of a particular article across the roller, and each of the rollers in each set is axially offset relative to each of the rollers in each adjacent set.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a showcase structure on which goods or articles such as foods or drinks packed in cans or bottles, i.e., canned foods or drinks and bottled drinks, etc. are placed for sale in shops, such as supermarkets, drugstores, convenience stores and the like. Usually, such a showcase structure comprises a roller support frame that is arranged so as to have a down-slope from the rear end toward the front end of the roller support frame and on which a plurality of parallel sets of rollers are mounted. The rollers in each parallel set of rollers are mounted rotatably on the roller support frame and arranged one after another from the rear end toward the front end of the roller support frame. Individual articles, such as canned drinks, may be placed across two or more parallel sets of the rollers so that the articles can be moving or sliding down one by one along those rollers from the rear end toward the front end.

[0003] More specifically, the present invention relates to a showcase assembly unit for such showcase structure.

[0004] 2. Prior Art

[0005]FIG. 7 represents a showcase structure that is installed in shops such as supermarkets, drugstores, convenience stores and the like, and FIG. 8 shows a conventional showcase assembly unit that is designed for use with the showcase structure shown in FIG. 7.

[0006] As shown in FIG. 8, the showcase assembly unit includes a roller support frame 1 that is arranged so as to have a down-slope from the rear end toward the front end and on which a plurality of parallel sets of rollers A, B, etc. are mounted across the roller support frame 1. The rollers in each set A, B are rotatably mounted and arranged one after another from the rear end toward the front end. And the rollers in each set A, B are arranged in parallel with the rollers in each adjacent set across the roller support frame. For example, as shown in FIG. 8 and FIG. 10, the set A includes a plurality of rollers 2 a, 2 b, etc. arranged one after another from the rear end toward the front end of the roller support frame 1, and the set B includes a plurality of rollers 12 a, 12 b, etc. arranged similarly and in parallel with the set of rollers A across the roller support frame 1.

[0007] The rollers in each set A, B, such as the roller 2 a, etc. are each mounted so rotatably as to permit the articles thereon to roll or slide down one by one toward the front end, in the respective directions indicated by arrows 41 or 42 in FIG. 9.

[0008] Then, when a consumer picks one up that is shown at the foremost end 45, as shown by an arrow 46 in FIG. 8, from the articles placed in series on a particular set of rollers, such as the sets A and B in this case, in the showcase structure in FIG. 7, the articles 47 that follow the article 45 just picked up will automatically move down toward the front end one by one along the rollers as shown by arrow 48 in FIG. 8.

[0009] It may be seen from FIG. 10 that the conventional showcase assembly unit for the showcase structure includes several parallel sets of rollers A, B, C, D that are mounted across the showcase assembly unit, in which the respective rollers in any two adjacent sets are axially aligned with each other. For example, each of the rollers 2 a, 2 b, 2 c, etc. in the set A is axially aligned with each adjacent one of the rollers 12 a, 12 b, 12 c, etc. in the set B.

[0010]FIG. 9 represents the conventional showcase assembly unit for the showcase structure shown in FIGS. 8 and 10, which shows the sequence of rollers as viewed from the side to explain how a particular article such as canned drinks moves (slides) on the rollers. FIG. 9 also shows, as an enlarged scale, that the bottom of the article makes contact with the top of the sequence of the rollers.

[0011] It may be noticed, as shown in FIG. 10 each of the rollers in the set A is axially aligned with each adjacent one of the rollers in the set B parallel with the set A. For example, the roller 2 a in the set A is axially aligned with the adjacent roller 12 a in the set B. Similarly, the roller 2 b in the set A is axially aligned with the adjacent roller 12 b in the set B.

[0012] As viewed from the side of the roller sequence as shown in FIG. 9, the roller 12 a in the set B is hidden behind the roller 2 a in the set A, and the roller 12 b is hidden behind the roller 2 b in the set A.

[0013] As shown in FIG. 9, there is a large gap S that is created on the top between the adjoining rollers 2 a and 2 b in the set A as well as between the adjoining rollers 12 a and 12 b in the set B which are not seen behind the rollers 2 a and 2 b.

[0014] Thus, when an article 5, such as canned drinks, is moving along the rollers in the parallel sets A and B as shown in FIG. 10, the article must overcome the large gap S on the top between the rollers 2 a and 2 b and between the rollers 12 a and 12 b, between the rollers 2 b and 2 c, and between the rollers 12 b and 12 c, etc.

[0015] This gap S (FIG. 9) may have a different size, depending on the diameters of the adjoining rollers, for example, the rollers 2 a and 2 b and the rollers 12 a and 12 b, and depending on the interval between the outer surfaces of adjoining rollers, for example, between the outer surfaces of the rollers 2 a and 2 b, etc.

[0016] In any case, as each of the rollers 2 a, 2 b, 2 c, etc. in the set A is axially aligned with each adjacent one of the rollers 12 a, 12 b, 12 c, etc. in the set B as shown in FIG. 10, the gap S on the top between the respective adjoining rollers in the parallel sets of roller, for example, the rollers 2 a and 2 b in the set A and the rollers 12 a and 12 b in the set B, must be larger as viewed from the side in FIG. 9.

[0017] When an article 5 is moving down along the rollers, as indicated by an arrow 48 in FIG. 8, it may cause a jolting motion, producing large noise and friction each time it goes past the gap S between the adjoining rollers.

[0018] When the article 5 is moving from the position shown by phantom lines 5 a to the position shown by phantom lines 5 b in FIG. 9, it cannot be kept at the constant level or height, because the large gap S exists between the adjoining rollers 2 a and 2 b in the set A as well as between the adjoining rollers 12 a and 12 b in the set B (not seen), as viewed from the side in FIG. 9. Thus, each time the article 5 is moving past the large gap S, it may cause a jolting motion and produce large noise. It may be seen in FIG. 9 that the article is higher when it is placed in the position 5 b than when it is placed in the position 5 a.

[0019] It may be understood from the forgoing description that when a number of individual articles that are placed one after another on the rollers from the rear end toward the front end of the roller support frame are moving down one by one, as shown by arrow 48 in FIG. 8, the individual articles may receive the force that prevents them from moving forward, depending on the particular shape of the bottom of the article and the particular physical size of the article.

[0020] This problem may be solved by two possible ways. One way is to incline the roller support frame more greatly so that the articles can overcome the force that resists their movement. The other way is to make the outer diameter of each individual roller as small as possible and to make the interval between the outer surfaces of adjoining rollers as small as possible so that the gap S (FIG. 9) that is created on the top between the adjoining rollers 2 a and 2 b, for example, can be smaller.

[0021] In the former case, however, the articles may be moving forward rapidly, as indicated by arrow 48. Thus, some adequate means must be provided for preventing any one of the following articles 47 from jumping out. Otherwise, the articles 47 that follow the foremost article 45 may exert the greater force against the article 45 as indicated by arrow 48, which makes it difficult for a consumer to pick the article 45 up. For the latter case, additional manufacturing costs would be incurred, and the easy maintenance would be impossible.

SUMMARY OF THE INVENTION

[0022] An object of the present invention is to solve the problems associated with the conventional showcase assembly unit for the showcase structure as described above, and therefore to propose to provide a showcase assembly unit for the showcase structure in which individual commercial articles represented by foods or drinks packed in cans or bottles, that is, canned foods or drinks, may be placed one after another along and across the rollers so that when those articles are moving from the rear end toward the front end one by one, each one can be moving with stability while it is maintained all the way at a constant height, without causing a jolting motion or producing large noise, and with less frictional force.

[0023] In order to attain the above object, the showcase assembly unit for the showcase structure proposed by the present invention may comprise the following elements.

[0024] Generally, the showcase assembly unit includes a roller support frame, and a plurality of parallel sets of rollers mounted on the roller support frame. The rollers in each set are rotatably mounted on the roller support frame and arranged one after another from the rear end toward the front end of the roller support frame.

[0025] More specifically, a first set of rollers is mounted on the roller support frame. The rollers in this first set of rollers are rotatably mounted on the roller support frame and arranged one after another from the rear end toward the front end of the roller support frame. A second set of rollers is mounted on the roller support frame in parallel with the first set of rollers and adjacenting to the first set of rollers. The rollers in this second set of rillers are rotatably mounted on the roller support frame and arranged one after another from the rear end toward front end of the roller support frame. Other sets of rollers are also mounted in the same manner as for the first and second sets of rollers. Individual articles, such as foods or drinks packed in cans or bottles, i.e., canned foods or drinks, and bottled drinks, etc., may be placed across the adjacent sets of rollers so that the individual articles can move down one by one along the rollers toward the front end of the roller support frame.

[0026] Each of the rollers in each of the plurality of parallel sets of rollers has a predetermined width that is smaller than the size of the bottom of a particular individual article across said each of the rollers, so as to permit the individual articles to be placed across the two or more rollers in the sets adjacent to each other. And each of rollers in each of adjacenting parallel sets of rollers is axially offset relative to each adjacent one of the rollers in each adjacent set in the direction from the rear end toward the front end of the roller support frame.

[0027] A single article, such as canned drinks or bottled drinks, may be placed across two or more adjacent parallel set of rollers as each roller is less wider than the size of the bottom of the article across the roller, and is capable of moving across and along those rollers toward the front end of the roller support frame.

[0028] More specifically, for the sets of rollers A and B adjacent to each other, for example, each of the rollers 2 a, 2 b, 2 c, etc. in the set A is axially offset relative to each adjacent one of the rollers 12 a, 12 b, 12 c, etc. in the set B.

[0029] When those sets of rollers A and B are viewed from the side, the rollers 12 a, 12 b, 12 c, etc. in the set B are visible although they are placed behind the rollers 2 a, 2 b, 2 c, etc. in the set A, as shown in FIG. 2(a). Thereby, a gap S that is created on the top between any two adjoining rollers in the direction from the rear end toward the front end of the roller support frameviewed from the side can be smaller than that found in the prior art shown in FIG. 9.

[0030] Then, when a particular article that is placed across the rollers in the adjacent sets A and B is moving forward along the rollers, passing over the gap S created on the top between the two adjoining rollers in the direction from the rear end toward the front end of the roller support frame, respectively, it can be moving while its height is maintained to be constant all the way, because the gap S is smaller and the article is supported by the outer top sides of any two adjoining rollers 2 a, 2 b, 2 c, etc. in the set A and by the outer top sides of any two adjoining rollers 12 a, 12 b, 12 c, etc. in the set B adjacent to the set A. As the article can be moving in this way, it will not be jolting or produce any vibrations or large noise.

[0031] Each of the rollers in one set, such as the set A in this case, may be axially offset relative to each adjacent one of the rollers in the other set, such as the set B, by the distance that is equal to one half to one fourth the interval between the two adjoining rollers in the set A or B, as measured from axis to axis.

[0032] The offset of each roller in one set relative to each adjacent roller in the other set may be adjusted, depending on the diameter of the roller or the size of the bottom of a particular article across the roller.

[0033] When the offset is set to the value that is equal to one half the axis-to-axis interval between the two adjoining rollers, for example, the article can be moving with stability and without causing any jolting motion or producing any large noise.

[0034] If the offset is set to any smaller value, such as one third, one fourth or much smaller, the article can be moving with the less jolting motions or noise. In any way, the offset value should be determined by considering the manufacturing costs and the easiness in the maintenance. In this respect, the offset should preferably be set to any value between one half and one fourth.

[0035] Referring now to FIG. 5, the roller support frame 1 is described in detail. The roller support frame 1 includes a lower bearing segment 3 and an upper bearing segment 4 that is mounted on the lower bearing segment 3.

[0036] More specifically, the lower bearing segment 3 has a flat surface on its upper side that supports each parallel set of rollers so that the respective roller shafts can be maintained on the same plane. The upper bearing segment 4 has a recess for accepting the respective roller shafts, which is located on the lower side of the upper bearing segment 4 facing opposite the upper side of the lower bearing segment 3 and is positioned to face opposite the flat surface on the lower bearing segment 3.

[0037] Preferably, the recess on the upper bearing segment 4 should have the depth that is at least equal to the diameter of each roller shaft, and should have the bottom that is curved to conform to the outer peripheral wall of each roller shaft.

[0038] In this way, each of the roller shafts in each parallel set may be supported so that the roller shafts can be placed on the same plane. Thus, the rollers can have the identical height that meets the practical allowable precision requirements. As such, the articles can be moving without causing any jolting motion or vibrations.

[0039] As each roller shaft is supported by the flat surface of the lower bearing segment, the lower side (weight transmitting side) of each roller shaft can make contact with the flat surface of the lower bearing segment both linearly and circularly. This is substantially equivalent to the linear contact, which may reduce the rotational friction considerably. Therefore, the contact area may be reduced accordingly, which prevents dusts from building up there.

[0040] As each roller shaft is supported by the flat surface of the lower bearing segment as described above, the recess that is provided on the lower side of the upper bearing segment for accepting the roller shafts may only serve as the positioning means for the rollers. Therefore, the recess needs not to accept the total periphery of each roller shaft. This permits the contact area between each roller shaft and the inner peripheral wall of the recess to be extremely smaller, but this may meet the object of the present invention. What is required in this case is that the recess has the depth that is equal to the diameter of each roller shaft and that the bottom of the recess is curved to conform to the outer peripheral wall of each roller shaft.

[0041] It should be understood that the present invention is not limited to any particular shape of the recess, and the recess may have the inner peripheral wall formed like a curve or angle.

[0042] One advantage of the present invention is that it permits goods or articles such as canned drinks or bottled drinks to be maintained at a constant height all the way, when they are moving along the rollers from the rear end toward the front end of the showcase assembly unit. Thus, the individual articles can be moving with stability and without causing any jolting motion or producing any large noise.

[0043] Another advantage of the present invention is that many rollers can be mounted in the identical plane with high precision, and those rollers can rotate with less friction force.

BRIEF DESCRIPTION OF THE DRAWINGS

[0044]FIG. 1 is a plan view showing part of the roller arrangement according to one preferred embodiment of the present invention;

[0045]FIG. 2(a) is a side elevation view of the embodiment shown in FIG. 1, with some parts omitted for clarity of explanation;

[0046]FIG. 2(b) is a side elevation view of a variation of the embodiment in FIG. 1, in which the roller support frame comprising the lower bearing segment and upper bearing segment is modified, with roller shafts omitted for clarity of explanation;

[0047]FIG. 3 is a plan view showing part of the roller arrangement according to another preferred embodiment of the present invention;

[0048]FIG. 4(a) is a side elevation view of the embodiment shown in FIG. 3;

[0049]FIG. 4(b) is a side elevation view of a variation of the embodiment in FIG. 3, in which the roller support frame comprising the lower bearing segment and upper bearing segment is modified, with roller shafts omitted for clarity of explanation;

[0050]FIG. 5 is a partly enlarged sectional view that is presented to help understand how the rollers are mounted in the showcase assembly unit for the showcase structure according to the embodiment in FIG. 1;

[0051]FIG. 6 is a side elevation view that is presented to help understand how the articles are moving along the rollers in the showcase assembly unit for the showcase structure according to the embodiment in FIG. 1;

[0052]FIG. 7 is a perspective view showing the showcase structure for which the showcase assembly unit according to the present invention may be used, with some parts omitted;

[0053]FIG. 8 is a perspective view of the prior art showcase assembly unit in the showcase structure;

[0054]FIG. 9 is a side elevation view that is presented to help understand how the articles are moving along the rollers in the prior art showcase assembly unit for the showcase structure;

[0055]FIG. 10 is a plan view showing part of the roller arrangement according to the prior art showcase assembly unit for the prior art showcase structure.

DETAIS OF THE PREFERRED EMBODIMENTS

[0056] Referring to FIGS. 1 through 6, the embodiments of the present invention are now described in further details.

[0057] Referring first to FIG. 1, there is shown a showcase assembly unit for the showcase structure according to the present invention, which includes a roller support frame 1 and a plurality of parallel sets of rollers 2 a to 2 d, etc., 12 a to 12 d, etc., 22 a to 22 c, etc., 32 a to 32 c, etc. that are mounted on the roller support frame 1. The rollers in each set of rollers being mounted rotatably on the roller support frame 1 and arranged one after another from the rear end toward the front end of the roller support frame 1 and in parallel with each adjacent sets A, B, C and D.

[0058] More specifically, the parallel sets of rollers includes four sets of rollers A, B, C, and D, for example, that are arranged in parallel with each other in the direction perpendicular to the direction of the roller support frame 1 from the rear end toward the front end. Each of the sets A, B, C, and D includes a plurality of rollers 2 a to 2 d etc., 12 a to 12 d etc., 22 a to 22 c etc., and 32 a to 32 c, etc., respectively, that are rotatably mounted on the roller support frame 1 and are arranged one after another from the rear end toward the front end of the roller support frame 1.

[0059] Here, the phrase “from the rear end toward the front end of the roller support frame 1” should be understood to mean “from the top end toward the bottom end” in the plane of the drawing, as shown in FIG. 1. The phrase “the rollers 2 a, etc. are rotatably mounted” should be understood to mean that the rollers are rotatably mounted in the respective directions shown by arrows 41 or 42 in FIG. 2(a).

[0060] In the each set of rollers A, B, C and D, the interval between any two adjoining rollers in the direction from the rear end toward the front end of the roller support frame 1 is kept at constant. That is to say, as shown in FIGS. 1 and 3, the interval between the rollers 2 a and 2 b is as same as that of between the rollers 2 b and 2 c, 2 c and 2 d, 12 a and 12 b, 12 b and 12 c, 22 a and 22 b, etc.

[0061] Individual articles, such as canned foods or drinks, may be placed across the two or more adjacent sets of rollers A, B, C, D, and may move or slide one by one along the rollers from the rear end toward the front end of the roller support frame 1. In FIG. 1, an article 5, as represented by phantom lines, is placed across the two parallel sets of rollers A and B, moving toward the bottom end in FIG. 1.

[0062] When the showcase assembly unit as described above is installed in the showcase structure, it may be done so that the roller support frame 1 descends from the rear end toward the front end thereof, specifically, from the top end toward bottom end in FIG. 1 so as to permit the individual articles to move or slide one by one along the rollers in the sets A, B, C, D from the rear end toward the front end of the roller support frame 1.

[0063] In the showcase assembly unit according to the present invention, each roller 2 a, 12 a, 22 a, 32 a, etc. has a width that is smaller than the size of the bottom of the article 5 across the roller.

[0064] Thus, individual articles are placed across at least two or more adjacent sets of rollers, such as A, B, C and D, rather than a single set of rollers, and may be moving one by one along those sets of rollers. In the example shown in FIG. 1, the article 5 is moving along the adjacent sets of rollers A and B.

[0065] In the showcase assembly unit according to the present invention, the parallel sets of rollers A, B, C and D are arranged such that each of the respective rollers 2 a to 2 d,etc. in the set A, 12 a to 12 d, etc. in the set B, 22 a to 22 c, etc. in the set C 32 a to 32 c in the set D is offset relative to each adjacent one of the rollers in the adjacent sets, in the direction from the rear end toward the front end of the roller support frame 1.

[0066] More specifically, it may be seen in FIG. 1 that for the sets of rollers A and B adjacent to each other, for example, each of the rollers 2 a, 2 b, 2 c, etc. in the set A is offset relative to each adjacent one of the rollers 12 a, 12 b, 12 c, etc. in the set B, by the distance that is equal to one half the interval between any two adjoining rollers, as measured from the axis of one roller to the axis of the other roller.

[0067] When those two sets of rollers are viewed from the side, the rollers 12 a, 12 b, 12 c, 12 d in the set B are visible although they are placed behind the rollers 2 a, 2 b, 2 c, 2 d in the set A, as shown in FIG. 2(a). For example, the roller 12 a in the set B appears between the rollers 2 a and 2 b in the set A.

[0068] As viewed from the side in FIG. 2(a), the gap S that is created on the top between the two adjoining rollers in the set A as well as by the two adjoining rollers in the set B is smaller than the gap found in the prior art shown in FIG. 9.

[0069] When the article 5, which is placed across the two adjacent sets of rollers A and B as shown in FIG. 1, is moving along the rollers as shown by arrow 49 in FIG. 6, it may be moving from the rear end toward the front end of the roller support frame 1, while its height is maintained to be almost constant all the way. This is because the gaps S that the article 5 encounters on the way is relatively small, and the article 5 can smoothly move past those gaps S. This ensures that the article 5 is supported by the outer top sides of the rollers 2 a, 2 b, 2 c, 2 d, etc. in the set A as well as by the outer top sides of the rollers 12 a, 12 b, 12 c, 12 d, etc. in the set B. Thus, the article 5 will not produce any jolting motion or large noise, or will not receive any extra resistance when it is moving past each gap S.

[0070] Referring again to FIG. 2(a), the roller support frame 1 includes a lower bearing segment 3 and an upper bearing segment 4 mounted on the lower bearing segment 3.

[0071] Specifically, the lower bearing segment 3 has a flat surface 52, 52 (FIG. 5) on its upper side for supporting the rotary shafts 51 for the respective rollers 2 a to 2 d, etc. 12 a to 12 d, etc., 22 a to 22 c, etc., 32 a to 32 c, etc. so that the rollers can be maintained in the identical plane.

[0072] The upper bearing segment 4 has a recess 50 for accepting the roller shafts 51, which is located on the lower side of the upper bearing segment 4 facing opposite the upper side of the lower bearing segment 3, and is provided in the position corresponding to the flat surface 52, 52 on the lower bearing segment 3.

[0073] Each of the rotary shafts 51 for the respective rollers 2 a to 2 d, etc., 12 a to 12 d, etc., 22 a to 22 c, etc., 32 a to 32 c, etc. in the sets A, B, C, D may be supported on the flat surface 52 on the lower bearing segment 3 as if all the rotary shafts are supported in the identical plane.

[0074] As each roller shaft 51 is supported on the flat surface 52 on the lower bearing segment 3, it may make linear contact with the flat surface 52. This reduces the rotational friction considerably.

[0075] The recess 50 on the lower side of the upper bearing segment 4 may have the depth that is equal to the diameter of each roller shaft 51, and may have the bottom that is curved to conform to the outer peripheral wall of each roller shaft 51.

[0076] The embodiment shown in FIG. 2(b) is a variation of the embodiment shown in FIG. 2(a), wherein the lower bearing segment 3 has the recess 50 on its upper side for accepting each roller shaft 51, and the upper bearing segment 4 has the flat surface on its lower side facing opposite the lower bearing segment 3. In this case, the inner bottom wall of the recess 50 makes contact with the outer peripheral wall of each roller shaft 51, which may increase the rotational friction. However, the flat surface of the upper bearing segment 4 may act to hold down each roller shaft 51.

[0077]FIG. 3, FIG. 4(a), and FIG. 4(b) correspond to FIG. 1, FIG. 2(a), and FIG. 2(b), respectively.

[0078] In the embodiment shown in FIG. 3, the parallel sets of rollers A, B, C, D are shown, in which each of the rollers 2 a, 2 b, 2 c, etc. in the set A is offset relative to each adjacent one of the rollers 12 a, 12 b, 12 c, etc. in the set B, which in turn is offset relative to each adjacent one of the rollers 22 a, 22 b, 22 c, etc. in the set C. The value for the offset in each case may be set equal to one third the axis-to-axis interval between any two adjoining rollers in the sets A, B, C, such as between the adjoining rollers 2 a and 2 b in the set A, for example.

[0079] When the rollers in the sets A, B, C and D are then viewed from the side in FIG. 4(a), the roller 12 a in the set B and the roller 22 a in the set C may appear between the rollers 2 a and 2 b in the set A. Thus, the gap S created on the top between the respective adjoining rollers in the adjacent sets may become smaller than that shown in FIG. 2(a), as viewed from the side in FIG. 4(a).

[0080]FIG. 3 and FIG. 4(a) illustrate the embodiment in which the gap S may be reduced further, when it is compared with the gap in the embodiment shown in FIG. 1 and FIG. 2(a). According to this embodiment in FIG. 3 and FIG. 4(a), it is found that articles may be moving with less friction and less noise.

[0081] In the embodiment shown in FIG. 1 and FIG. 2(a) and in the embodiment shown in FIG. 3 and FIG. 4(a), the four parallel sets of rollers A, B, C, D are provided, but the present invention may be implemented by providing any other number of parallel sets of rollers, such as two sets of rollers A and B, three sets of rollers, five sets of rollers, and six sets of rollers.

[0082] Although the present invention has been described with reference to the particular embodiments thereof, it should be understood that the present invention should not be limited to those embodiments, but various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims. 

What is claimed is:
 1. A showcase assembly unit for the showcase structure including a roller support frame and a plurality of parallel sets of rollers mounted on said roller support frame, the rollers in each set of rollers being mounted rotatably and arranged one after another from the rear end toward the front end of said roller support frame, in which a plurality of commercial articles may be placed across the rollers in two or more adjacent sets on said roller support frame, and may be moving one by one along the rollers from the rear end toward the front end of said roller support frame, wherein each of the rollers in each of the plurality of parallel sets of rollers has a width that is smaller than the size of the bottom of a particular individual commercial article across said each of the rollers, and each of the rollers in each of adjacenting parallel sets of rollers is axially offset relative to each adjacent one of the rollers in each adjacent set in the direction from the rear end toward the front end of the roller support frame.
 2. The showcase assembly unit for the showcase structure as defined in claim 1 , wherein each of the rollers in each of the plurality of parallel sets is axially offset relative to each adjacent one of the rollers in each adjacent set in the direction from the rear end toward the front end of the roller support frame, by the distance that is equal to one half to one fourth the interval between the two adjoining rollers in each of the plurality of parallel sets of rollers, as measured from the axis of one roller to the axis of the adjoining other roller in the direction from the rear end toward the front end of the roller support frame.
 3. The showcase assembly unit for the showcase structure as defined in claim 1 , wherein said roller support frame includes a lower bearing segment and an upper bearing segment mounted on said lower bearing segment, and wherein said lower bearing segment has a flat surface on its upper side for supporting the rotary shaft for each of the rollers in each of the plurality of parallel sets of rollers so that said each rotary shaft can be maintained in the identical plane, and said upper bearing segment has a recess on its lower side facing opposite the upper side of said lower bearing segment and located in the position corresponding to the flat surface of said lower bearing segment, for accepting said each rotary shaft therein.
 4. The showcase assembly unit for the showcase structure as defined in claim 2 , wherein said roller support frame includes a lower bearing segment and an upper bearing segment mounted on said lower bearing segment, and wherein said lower bearing segment has a flat surface on its upper side for supporting the rotary shaft for each of the rollers in each of the plurality of parallel sets of rollers so that said each rotary shaft can be maintained in the identical plane, and said upper bearing segment has a recess on its lower side facing opposite the upper side of said lower bearing segment and located in the position corresponding to the flat surface of said lower bearing segment, for accepting said each rotary shaft therein.
 5. The showcase assembly unit for the showcase structure as defined in claim 3 , wherein said recess on said upper bearing segment has a depth that is at least equal to the diameter of said each rotary shaft, and has the bottom that is curved to conform to the outer peripheral wall of said each rotary shaft.
 6. The showcase assembly unit for the showcase structure as defined in claim 4 , wherein said recess on said upper bearing segment has a depth that is at least equal to the diameter of said each rotary shaft, and has the bottom that is curved to conform to the outer peripheral wall of said each rotary shaft. 